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author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2017-11-20 08:08:30 +0100 |
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committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2017-11-20 08:08:30 +0100 |
commit | 70f23e475b23af25e2035e2b5cfe1f5a8a7ea9f9 (patch) | |
tree | c9a5e6d943e3e42820b431f0a25658970a8dbbe5 /bsp-howto | |
parent | e2a1a3ab2a4d137c3a68250c9f1ddc5f2d9af7e4 (diff) |
Clarify INTERNAL_ERROR_ARC4RANDOM_GETENTROPY_FAIL
Update #3239.
Diffstat (limited to 'bsp-howto')
-rw-r--r-- | bsp-howto/getentropy.rst | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/bsp-howto/getentropy.rst b/bsp-howto/getentropy.rst index b460450..10303a3 100644 --- a/bsp-howto/getentropy.rst +++ b/bsp-howto/getentropy.rst @@ -21,7 +21,10 @@ turn are used by various cryptographic functions. suitable for such applications. The :c:func:`getentropy` implementation must fill the specified memory region -of the given size with random numbers and return 0 on success. +of the given size with random numbers and return 0 on success. A non-zero +return may cause the :c:macro:`INTERNAL_ERROR_ARC4RANDOM_GETENTROPY_FAIL` +internal error by one of the +`ARC4RANDOM(3) <https://man.openbsd.org/arc4random.3>`_ functions. In general, for embedded systems it is not easy to get some real entropy. Normally, that can only be reached with some extra hardware support. Some microcontrollers |